Water-cooled power conversion system

Abstract

A water-cooled power conversion system capable of reliably bleeding air in a short time is provided by simultaneously injecting cooling water and bleeding air into a main circuit unit. The water-cooled power conversion system consists of a main circuit board, a water supply apparatus, and a cooling apparatus, and the main circuit unit in the main circuit board comprises pressure-contacted semiconductor elements, water-cooled heat sinks arranged upper and lower surfaces of, and in close contact with the pressure-contacted semiconductor element, and an air bleeding valve located above the water flow pipe. The main circuit board includes a drain hose for flowing cooling water overflowing with air from the air bleeding valve, a drain pan for storing the cooling water discharged from the drain hose, a leak sensor for detecting the cooling water of the drain pan, and a control unit. The cooling apparatus includes a pump that pressurizes cooling water and injects water into the water-cooled heat sink, and the control unit operates the air leakage valve and the pump when the amount of water in the drain pan exceeds a predetermined value, control to finish injecting cooling water and bleeding air at the same time.

1 . A water-cooled power conversion system equipped with a main circuit board, a water supply apparatus, and a cooling apparatus, 
       wherein,
 the main circuit board comprises:
 a plurality of main circuit units with same configuration; 
 same number of drain houses as the number of the main circuit units; 
 same number of drains as the number of the main circuit units; 
 same number of leakage sensors as the number of the main circuit units; 
 
 a control unit;
 the main circuit unit involves:
 semiconductor elements; 
 water-cooled heat sinks arranged so as to contact with cooling surface of the semiconductor elements; 
 
 a water outlet through which cooling water cooled by the cooling apparatus is passed through the water-cooled heat sink; 
 a drain port for draining the cooling water taken into the main circuit unit from the water outlet; 
 a pipe connecting the cooling apparatus to the water outlet or the drain, or between the water outlet and the water-cooled heat sink so that cooling water flow; 
 an air bleeding valve located at the top of the pipe connecting the water outlet and the water-cooled heat sink; 
 
 one end of the drain hose is connected to the air bleeding valve of the plurality of main circuit units, and the other end is configured so that water flowing through the drain hose from the air bleeding valve is flowed to the drain, 
 the water leakage sensor outputs a water leakage detection signal when the flow rate of the cooling water flowed to the drain exceeds a predetermined value, 
 the control unit is connected so as to be able to receive the leak detection signal from the leak sensor, 
 the water supply apparatus is equipped with a surge tank and a water supply port, and the water supplied from the water supply port is stored in the surge tank, and the water is supplied to the cooling apparatus, 
 the cooling apparatus is equipped with a pump that pressurizes the cooling water supplied from the surge tank and the water discharged from the drain port, and injects the water into the water-cooled heat sink through the pipe and the water outlet, and, 
 the pump is connected so as to be able to control its start and stop operation from the control unit. 
 
     
     
         2 . The water-cooled power conversion system according to  claim 1 , wherein
 the surge tank is provided with a first water level sensor that detects the first water level, and when the first water level sensor detects that the water level is less than the first water level, the pump is stopped and water is injected into the surge tank from the water supply port so that the water level of the surge tank is kept above a predetermined water level, and   the air bleeding valve is installed at a position lower than the first water level of the surge tank, wherein after the pump is operated for a first predetermined period of time, the pump is stopped, the air bleeding valve is opened, and an air bleeding procedure is performed.   
     
     
         3 . The water-cooled power conversion system according to  claim 2 , wherein
 the air bleeding valve is composed of valves that can be operated by opening/closing commands from the control unit,   The control unit outputs a closing command to the air bleeding valve corresponding to the water leakage detection signal, when the control unit receives the water leakage detection signal from the water leakage sensor, and   the air bleeding procedure is completed when the control unit receives the water leakage detection signals from all the water leakage sensors within a period not exceeding the second predetermined time from the opening command of the air bleeding valve.   
     
     
         4 . The water-cooled power conversion system according to  claim 2 , wherein
 the air bleeding valve is composed of valves that can be operated by opening/closing commands from the control unit,   the control unit involves;
 as a first procedure, the pump is operated for a first predetermined period; 
 as a second procedure, stop the pump; 
 as the third procedure, the air bleeding valve open command is outputted and when the control unit receives the water leakage detection signal from the water leakage sensor, a closing command is outputted to the air bleeding valve corresponding to the water leakage detection signal; 
 as a fourth procedure, when a closing command is outputted to all the air bleeding valves, the process proceeds to a fifth procedure. 
 as the fifth procedure, when the number of repetitions from the first procedure to the fourth procedure is less than a predetermined number, the process returns to the first procedure, and when the number of repetitions is more than a predetermined number, the air bleeding procedure is completed. 
   
     
     
         5 . The water-cooled power conversion system according to  claim 2 , wherein
 the drain hose is equipped with an auxiliary air bleeding valve on the drain side, and   the control unit further comprising circuit for notifying the operator of the operating state of the pump and the water leakage detection signal, and circuit for electrically receiving signal that the auxiliary air bleeding valve closed by and the operator or the interlocking signal with the auxiliary air bleeding valve.   
     
     
         6 . The water-cooled power conversion system according to  claim 1 , wherein
 the surge tank is equipped with a first water level sensor for detecting the first water level and a second water level sensor for detecting a second water level higher than the first water level, and   the operation of the pump is started after the water injection in the surge tank is completed up to the water level of the second water level sensor when starting water injection of the water-cooled power conversion system.   
     
     
         7 . A water-cooled power conversion system equipped with a main circuit board, a water supply apparatus, and a cooling apparatus, 
       wherein,
 the main circuit board comprises:
 a plurality of main circuit units with same configuration;
 same number of drain hoses as the number of the main circuit units; 
 same number of bubble sensors as the number of the main circuit units; 
 
 
 a control unit;
 the main circuit unit involves:
 semiconductor elements; 
 water-cooled heat sinks arranged so as to contact with cooling surface of the semiconductor elements; 
 
 a water outlet through which cooling water cooled by the cooling apparatus is passed through the water-cooled heat sink; 
 a drain for draining the cooling water taken into the main circuit unit from the water outlet; 
 a pipe connecting the cooling apparatus to the water outlet or the drain, or between the water outlet and the water-cooled heat sink so that cooling water flow; 
 an air bleeding valve located at the top of the pipe connecting the water outlet and the water-cooled heat sink; 
 
 one end of the drain hose is connected to the air bleeding valve of the plurality of main circuit units, 
 the bubble sensor is attached to the drain hose so that bubbles can be detected in the drain hose, and outputs a bubble detection signal when bubbles are detected, 
 the water flowing through the drain hose or the surge tank is flowed from the air bleeding valve, 
 the control unit is connected so as to be able to receive the bubble detection signal from the bubble sensor, 
 the water supply apparatus is equipped with a surge tank and a water supply port, and the water supplied from the water supply port is stored in the surge tank, and the water is supplied to the cooling apparatus, 
 the cooling apparatus is equipped with a pump that pressurizes the cooling water supplied from the surge tank and the water discharged from the drain port, and injects the water into the water-cooled heat sink through the pipe and the water outlet, and, 
 the pump is connected so as to be able to control its start and stop operation from the control unit. 
 
     
     
         8 . The water-cooled power conversion system according to  claim 7 , wherein
 a first water level sensor is provided to detect the first water level,   when the first water level sensor detects that the water level is less than the first water level, the pump is stopped and water is injected into the surge tank from the water supply port, and   the end of the drain hose on the surge tank side is arranged below the first water level.   
     
     
         9 . The water-cooled power conversion system according to  claim 7 , wherein
 the control unit terminates the air bleeding treatment when the bubble detection signal is not continuously received for a third predetermined period during the operation of the pump.